Method for the production of hydrogen



Nov. 17, 1931. R. E. BATTIG 1,831,943

METHOD FOR-THE PRODUCTION OF HYDROGEN Filed may 19. 1927' Patented Nov. 17, 1931 UNITED STATES PATENT .OFFICE RUDOLF E. BATTIG, OF SODINGEN, GERMANY, ASSIGNOR TD THE FIRM PATENTVER- WERTUNGS A. G. ALPINA, S. A. POUR LEXPLOITATION DE BREVETS ALPINA, PATENTS EXPLOITATION CY. ALPINA LTID.q OF BASEL, SWITZERLAND METHOD FOR THE PRODUCTION F HYDROGEN'V Application Jed Hay 19, 1927, Serial No. 192,806,` and in Germany May 20, 1926.

My invention refers to the production of hydrogen, more especially for the synthetical production of ammonia. Hitherto the hydrogen required for this purpose is produced either by treating iron oxide with reducing gases following oxidation by Water or steam or by the electrolytical decomposition of Water or from Dawson-gas.

It has further been suggested to recover the hydrogen present in great quantities in the coke oven gases obtained in gasifying channel coal, tar coal, Wood, cellulose and other substances containing carbon. The'coke oven gases obtained in gasifying channel coal contain about 45%-55% hydrogen, 1895-2670 methane, 8%-l2% carbon dioxide and. 1%- 2.5% higher boiling hydrocarbons.

I have now found that if this gaseous mixture is decomposed in a well known manner into its single components by compression expansion and liquefaction in consequence oi the drop of temperature accompanying expansion, the hydrogen which is not condensed being separated from the liquefied gases, these gases, When subjected to fractional distillation, yield a methane of high purity which, when decomposed in a well known manner, furnishes additional Very pure hydrogen, which can be admixed to the hydrogen gas originally recovered.

In this manner it is possible to produce at 10W cost great quantities of hydrogen of high purity from the coke oven gases.

The methane obtained by fractional distillation from the liquefied gas mixture is passed over incandescent coke, whereby the decomposition in its components (carbon and hydrogen) is efected.

As shown in the flow sheet aiiixed to this specification I may proceed in such manner, that the vmethane gas is introduced into a generator lled with coke and heated up to a temperature of about 1000" C. Alternatively I may pass the methane gas through the coke in the coke ovens. In either case the methane is decomposed into hydrogen and carbon which latter is deposited on the coke. As the process of decomposing the methane gas is an endothermic one, the temperature of the coke is thereby reduced, before the coke is removel from the ovens.

As the decomposition of the methane gas proceeds more slowly with the reduction of the concentration of the methane gas in consequence of its decomposition, the decomposition will not take place quantitatively, if he coke does not oli'er a sufficiently great surface or does not contain catalysts. I therefore prefer varying the velocity of iiow of the methane in proportion to the temperature of the coke and subjecting the gas mixture which has passed over the coke to fractional separation by compression, expansion and liquefaction. The hydrogen is thus recovered as a gas.

Various changes may be made in the details disclosed in the foregoing specification without departing from my invention or sacrificing the advantages thereof.

I claim:

The process of recovering hydrogen from coke-oven gases comprising subjecting the gas mixture to compression and expansion, accompanied by a drop of temperate, so as to liquefy all gases in the mixture except hydrou gen, separating the hydrogen gas, subjecting the remaining mixture of liqueiied gases to fractional distillation to separate methane decomposing the methane to hydrogen and carbon by passing the methane over the highly heated coke in the coke ovens, from which the original gas mixture had been recovered, and treating the gas mixture thus formedin the manner above recited.

In testimony whereof I aiix my signature.

RUDOLF E. BATTIG. 

